Abstract Optical fiber sensors (OFSs) have attracted more and more attention in the field of in-situ ocean observation because of their advantages of the small size, light weight, low cost, and intrinsic immunity to electromagnetic interference. Here, we comprehensively reviewed the development of various advanced physical and chemical OFSs for in-situ measurement of ocean key parameters, including temperature, salinity, pressure, acoustics, flow velocity and turbulence, potential of hydrogen (pH), heavy metal ion…

Ocean exploration-oriented temperature and salinity (TS) sensor based on bend-insensitive microfiber Mach-Zehnder interferometer (MMZI) is proposed and demonstrated in a marine environment. To solve the demodulation problem induced by the narrow waveband of the spectrometer used in the sea trial, a MMZI sensor is calibrated and demodulated by machine learning method. Results show that even if the wavelength range used in demodulation is as small as tens of nanometers, a relatively accurate demodulation can still b…

A robust strain sensor is demonstrated based on a microfiber Mach–Zehnder interferometer (MMZI) encapsulated by the polymer polydimethylsiloxane (PDMS). Benefiting from the low Young’s modulus of PDMS, both a robust structure and high sensitivity can be realized based on three different encapsulations. In the experiment, the proposed sensors are fabricated and tested with strain sensitivities ranging from −20.95 pm/με to 127.00 pm/με within the wavelength range of 1200–1650 nm. Compared with the bare MMZI sensor, …